/*
 * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 2001-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: ValueOf.java,v 1.2.4.1 2005/09/05 09:30:04 pvedula Exp $
 */

package com.sun.org.apache.xalan.internal.xsltc.compiler;

import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
import com.sun.org.apache.bcel.internal.generic.INVOKEINTERFACE;
import com.sun.org.apache.bcel.internal.generic.INVOKEVIRTUAL;
import com.sun.org.apache.bcel.internal.generic.InstructionList;
import com.sun.org.apache.bcel.internal.generic.PUSH;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ErrorMsg;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Util;

/**
 * @author Jacek Ambroziak
 * @author Santiago Pericas-Geertsen
 * @author Morten Jorgensen
 */
final class ValueOf extends Instruction {

  private Expression _select;
  private boolean _escaping = true;
  private boolean _isString = false;

  public void display(int indent) {
    indent(indent);
    Util.println("ValueOf");
    indent(indent + IndentIncrement);
    Util.println("select " + _select.toString());
  }

  public void parseContents(Parser parser) {
    _select = parser.parseExpression(this, "select", null);

    // make sure required attribute(s) have been set
    if (_select.isDummy()) {
      reportError(this, parser, ErrorMsg.REQUIRED_ATTR_ERR, "select");
      return;
    }
    final String str = getAttribute("disable-output-escaping");
    if ((str != null) && (str.equals("yes"))) {
      _escaping = false;
    }
  }

  public Type typeCheck(SymbolTable stable) throws TypeCheckError {
    Type type = _select.typeCheck(stable);

    // Prefer to handle the value as a node; fall back to String, otherwise
    if (type != null && !type.identicalTo(Type.Node)) {
      /***
       *** %HZ% Would like to treat result-tree fragments in the same
       *** %HZ% way as node sets for value-of, but that's running into
       *** %HZ% some snags.  Instead, they'll be converted to String
       if (type.identicalTo(Type.ResultTree)) {
       _select = new CastExpr(new CastExpr(_select, Type.NodeSet),
       Type.Node);
       } else
       ***/
      if (type.identicalTo(Type.NodeSet)) {
        _select = new CastExpr(_select, Type.Node);
      } else {
        _isString = true;
        if (!type.identicalTo(Type.String)) {
          _select = new CastExpr(_select, Type.String);
        }
        _isString = true;
      }
    }
    return Type.Void;
  }

  public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
    final ConstantPoolGen cpg = classGen.getConstantPool();
    final InstructionList il = methodGen.getInstructionList();
    final int setEscaping = cpg.addInterfaceMethodref(OUTPUT_HANDLER,
        "setEscaping", "(Z)Z");

    // Turn off character escaping if so is wanted.
    if (!_escaping) {
      il.append(methodGen.loadHandler());
      il.append(new PUSH(cpg, false));
      il.append(new INVOKEINTERFACE(setEscaping, 2));
    }

    // Translate the contents.  If the value is a string, use the
    // translet.characters(String, TranslatOutputHandler) method.
    // Otherwise, the value is a node, and the
    // dom.characters(int node, TransletOutputHandler) method can dispatch
    // the string value of the node to the output handler more efficiently.
    if (_isString) {
      final int characters = cpg.addMethodref(TRANSLET_CLASS,
          CHARACTERSW,
          CHARACTERSW_SIG);

      il.append(classGen.loadTranslet());
      _select.translate(classGen, methodGen);
      il.append(methodGen.loadHandler());
      il.append(new INVOKEVIRTUAL(characters));
    } else {
      final int characters = cpg.addInterfaceMethodref(DOM_INTF,
          CHARACTERS,
          CHARACTERS_SIG);

      il.append(methodGen.loadDOM());
      _select.translate(classGen, methodGen);
      il.append(methodGen.loadHandler());
      il.append(new INVOKEINTERFACE(characters, 3));
    }

    // Restore character escaping setting to whatever it was.
    if (!_escaping) {
      il.append(methodGen.loadHandler());
      il.append(SWAP);
      il.append(new INVOKEINTERFACE(setEscaping, 2));
      il.append(POP);
    }
  }
}
